nuttx/arch/sim/src/up_unblocktask.c

138 lines
4.8 KiB
C

/****************************************************************************
* arch/sim/src/up_unblocktask.c
*
* Copyright (C) 2007-2009, 2013, 2015 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sched.h>
#include <debug.h>
#include <nuttx/arch.h>
#include <nuttx/sched.h>
#include "clock/clock.h"
#include "sched/sched.h"
#include "up_internal.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: up_unblock_task
*
* Description:
* A task is currently in an inactive task list
* but has been prepped to execute. Move the TCB to the
* ready-to-run list, restore its context, and start execution.
*
* Inputs:
* tcb: Refers to the tcb to be unblocked. This tcb is
* in one of the waiting tasks lists. It must be moved to
* the ready-to-run list and, if it is the highest priority
* ready to run taks, executed.
*
****************************************************************************/
void up_unblock_task(struct tcb_s *tcb)
{
struct tcb_s *rtcb = (struct tcb_s*)g_readytorun.head;
/* Verify that the context switch can be performed */
ASSERT((tcb->task_state >= FIRST_BLOCKED_STATE) &&
(tcb->task_state <= LAST_BLOCKED_STATE));
sdbg("Unblocking TCB=%p\n", tcb);
/* Remove the task from the blocked task list */
sched_removeblocked(tcb);
/* Reset scheduler parameters */
sched_resume_scheduler(tcb);
/* Add the task in the correct location in the prioritized
* g_readytorun task list
*/
if (sched_addreadytorun(tcb))
{
/* The currently active task has changed! */
/* Update scheduler parameters */
sched_suspend_scheduler(rtcb);
/* Copy the exception context into the TCB of the task that was
* previously active. if up_setjmp returns a non-zero value, then
* this is really the previously running task restarting!
*/
if (!up_setjmp(rtcb->xcp.regs))
{
/* Restore the exception context of the new task that is ready to
* run (probably tcb). This is the new rtcb at the head of the
* g_readytorun task list.
*/
rtcb = (struct tcb_s*)g_readytorun.head;
sdbg("New Active Task TCB=%p\n", rtcb);
/* The way that we handle signals in the simulation is kind of
* a kludge. This would be unsafe in a truly multi-threaded, interrupt
* driven environment.
*/
if (rtcb->xcp.sigdeliver)
{
sdbg("Delivering signals TCB=%p\n", rtcb);
((sig_deliver_t)rtcb->xcp.sigdeliver)(rtcb);
rtcb->xcp.sigdeliver = NULL;
}
/* Update scheduler parameters */
sched_resume_scheduler(rtcb);
/* Then switch contexts */
up_longjmp(rtcb->xcp.regs, 1);
}
}
}